Treatment of hydrocarbon oils



July 23, 1935. c. H. ANGELL ,1

TREATMENT OF HYDROCARBON OILS Filed Jan. 11, 1952 INVENTOR CHARLES H. ANGELL BY mawjn z ATTOR Patented July, 23, 1 935 I Charles-H. Angeli, ChicagmllL, assignor I .versal Oil Products'Company, Chicago. .IlL, corporation of South Dakota H t v 1 Claim. (01.196 58) invention relates to the treatment'oi hydrocarbonoils .andniore' specifically refers to an i'mD Qved process and apparatus for separatlight desirable components such as gasolin'e from crude petroleum, accompanied by Pyrolyti'c .conversion'of heavier components of the crude.

It'isfthe,ipi'im i' yl object of the present invention 4 .to provide 'Yimpro'ved method I and means fortoppiiigfa'. crude oil and cracking the topped crude ina single, operation utilizing heat recovered fromjthe cracking system. as a means o'f topping" the crude oil and collecting, as the motor" fuel. product of; the system, a blend of the gasoline naturally contained in the crude "oil (straight-run gasoline) and products'of similar boiling rangefresulting fron'i cracking of heavier components of the crude.

The'invention comprises, in one of its specific embodiments, subjecting afcrude oil containing gasoline, to vaporization within a low pressure zone of a cracking system under substantially non-cracking conditions by direct contact with heated conversion products of the system, separating the resulting vaporous and non-vaporous products, subjecting the vapors comprising vapori'zed-portions ,of the crude and vaporous conversion products to fractionation whereby products of the desired motor fuel boiling range are separated from heavier products comprising insuiilciently converted intermediate conversion products and portions of the crude which are first vaporized and subsequently condensed 'by' fractionation to conversion conditions of elevated temperature and substantial super-atmospheric pressure in a heating element, introducing conversion products from the heating element into an enlarged reaction chamber where conversion, particularly of the vaporous products, is continued under super-amospheric pressure, introducing both liquid and vaporous conversion products from the reaction zone to the aforementioned reduced pressure zone to which the crude oil is likewise introduced and returning a portion of the non-vaporous products comprising heavy .nonvaporous components of the crude and residual liquid resulting from conversion to the stream of heated products entering the reaction chamber from the heating element.

Various modifications of the primary principles of the invention will be more specifically described in connection with the following description of the attached diagrammatic drawing. The drawing illustrates one specific form of apparatus suitable for the practice of the present in-- vention. Attention is particularly directed to the extreme I simplicity of the apparatus," indicating the adaptability of the principlesof the present invention to existing Referring now to the d l is located within1a'iur'n 2 of amt suitable form fro m"whichheat Rhuirdforj a l" ott ei 1 supplied t jtheilheatih ielemeii b 'der e -i T nea dfp ti ssesth d 3 and valve [into-reaction chaifibij which, like the heating element, s preferably aintaiiied a'i a substantial super-atmospheric press ij an wherein products jvapor'iz'ed are "subjected to continued-'conver'sion for a'jpredete'rmined time 'whilerelatively'fheavy non-vaporous products separate from the vapors andpass more rapidly to the lower portion of the chamber without substantial further conversion. f Both heating; element liquid and vaporousproducts' are withdrawn from chamber 5 through line 8 and valvefh'fpassing into vaporizing andl topping'jchamber ,8;

,Crude oil or 'other'raw oil charging 'stockior the system comprising a hydrocarbon oil containing a substantial proportion of gasoline or motor fuel fractions, mayi'ibe suppliedthrough line" 9 and valve [0 to 'pumpfll from which it may be fed through line I2, valve 13, preheating coil l4, line l5 and either through line [6 and valve I I into chamber 18 or through valve It, in line I5, into the lower portion of chamber 5, or', if desired, partially in both directions. The raw oil supplied chamber 5, as described, serves to dilute and cool the reaction products from this zone, passing through line; and valve 1 into chamber 8 thereby'subs'tantially preventing the formation of coke or carbonaceous material in this line'.- In either case, whether supplied directly to chamber 3 or lntolthe lower portion of chamber}, the charging stock is-further heated by direct contact with the reaction products from chamber 5 and its substantial vaporization is leflfected in chamber 8. It will be understood that other well known in thOdS of preheating the raw oil prior to its introduction into the topping chamber may be employed instead of or in conjunction with preheating .0011 It or, when desired, the raw-.oil may be and va'pors passing from vaporizing chamber 8 to fractionator l9 may be utilized.

Chamber 8 is preferably maintained at a substantially reduced pressure relative to that employed in chamber 5, which reduced pressure serves to assist vaporization of the non-vaporous oilintroduced into this zone, also serving to assist cooling of the conversion products from chamber -5; Oil remaining unvaporized in chamber 8 is withdrawn throughlinelfl and may be removed, all or in part, from the system through line 2| and valve 22 to cooling and storage or to any desired further treatment. Preferably, however, a portion of the oil withdrawn from chamber 8 passes through valve 23, in line 20, to pump 24 from which it is fed through line 25 and valve 26 into the upper portion of chamber 5, entering this zone either through an independent line, not shown, or first comingling in' line with the heated oil from heating element l and passing therewith to chamber 5.

. Vapors from chamber 8 pass through line 21 and valve 28 to fractionation in fractionator i9 by means of which the relatively heavy' components of the vaporized portion of the charging stock and insufllciently converted components of the cracked vapors are condensed, collecting in the lower portion of the fractionator to be withdrawn therefrom through line 29 and valve 30 to pump 3| from which they are fed through line 32 and valve 33 to heating element I for conversion. Relatively light vapors, comprising desirable components topped from the charging stock in chamber 8 ,and' the desirable cracked products are withdrawn from fractionator [9 through line 34 and valve 35, are subjected to condensation and cooling in condenser 36, distillate and uncondensable gas from which passes through line 31 and valve 38 to be collected in receiver 39.. Uncondensable gas may be released from the receiver through line 40 and valve 4i. Distillate may be withdrawn from receiver 39 through line 42 and valve 43.

In starting the operation of the process and in its initial stages, prior to the time when reflux condensate is produced in quantities sumcient to serve as the sole liquid heat carrying medium which is subjected to cracking in the heating element and thence utilized flrst to effect mild conversion of the unvaporized oil withdrawn from the low pressure chamber and subsequently to effect vaporization of the raw oil, some other oil must be substituted, all or in part, for the reflux condensate. The oil thus utilized as the heat carrying medium during the initial stages of the operation may be the regular raw oil charging stock for the system or, when desired, a lighter oil, more refractory to cracking, may be utilized for this purpose and in either case the supply of this material direct to the heating element is discontinued as soon as the production of reflux condensate is sufficient to maintain the desired regular operating conditions. Line l2, controlled by valve I3 is provided, connecting pump ii with line 32 leading to heating element i by means of which pump ll may supply the heat carrying medium to the heating element. This supply of raw 011 direct to the heating element may be gradually diminished as reflux condensate from fractionator I9 is supplied through line 29, valve 80, pump 3!, line 32 and valve 33 to the heating element until the reflux condensateentirely replaces the other oil, following which the supply of crude to reaction chamber 6 and/or to reduced pressure chamber 8 may be started and gradually increased until equilibrium conditions are reached.

Conversion temperatures employed at the outlet of the heating element preferably range from 900 to 1050 F. and substantial super-atmospheric pressure ranging, for example, from 100 to 500 pounds, or more, per square inch is preferably employed in both the heating element and reaction chamber although pressure in the reaction chamber may be somewhat reduced, when desired, relative to that employed in the heating element. The vaporizing, fractionating, condensing and collecting portions of the system preferably utilize relatively low pressures ranging, for -example, from 100 pounds per square inch down to substantiall atmospheric pressure.

As a specific example of the operation of the process of the present invention, a 32 A, P. I. gravity mid-continent crude oil containing about 15 percent of straightrun gasoline having an octane number of approximately 50 is the charging stock supplied to the system. Reflux condensate from the fractionator of the system is subjected in the heating element to a temperature of approximately 940 F. under a super-atmospheric pressure of approximately 400 pounds per square inch. This pressure is substantially equalized in the reaction chamber of the system where, by the recirculation of the residual oil from the vaporizing chamber, the temperature is reduced to approximately 890 F. This operation may yield approximately 78 percent of motor fuel having an antiknock value approximately equivalent to a mixture of percent iso-octane and 25 percent normal heptane. In addition about 15 percent of premiumfuel oil is produced as the residual product of the system, the remaining 7 percent or thereabouts being chargeable principally to uncondensable gas.

I claim as my invention:

A combined topping and cracking process which comprises heating reflux condensate, formed as hereinafter set forth, to cracking temperature under pressure in a heating zone, discharging the heated reflux into the upper portion of an enlarged vertical reaction zone maintained under cracking conditions of temperature and pressure and passing both vapors and liquid downwardly through the reaction zone, removing the vapors and liquid as a mixture from the lower portion of the reaction zone and commingling crude oil containing natural gasoline therewith, discharging the commingled oils into a separating zone maintained under lower pressure than the reaction zone and separating the same therein into vapors and unvaporized oil, commingling at least a portion'of said unvaporized oil with said heated reflux being discharged into the upper portion of the reaction zone, fractionating said vapors to condense heavier fractions thereof and supplying such condensed fractions to the heating zone as said reflux condensate, and finally condensing the fractionated vapors.

CHARLES H. ANGELL. 

